Vertical blinds have been used extensively for decorative coverings of windows, doors and the like. It has long been a practice to coordinate the color of louvers in such systems with the decor of the room. However, it is impractical to maintain an inventory of louvers in the tremendous number of different colors, shades and patterns used in contemporary styling.
In addition, when it is time to redecorate and coordinate the color of the louvered system to a new color scheme, it is necessary either to replace the louvers themselves or the entire vertical blind system. Adding a colored pattern to a vertical louver system has been difficult and expensive.
One way to attach a colored pattern to louvers is to permanently glue material onto the louvers. Another way to attach a colored pattern to louvers is disclosed in U.S. Pat. No. 4,628,980, to LeHouillier. There, each louver has flanges along its side edges into which strips of wallpaper or other stiff material are inserted. The strips must be cut precisely to be secured by the flanges. Even so, with changes in humidity or temperature, inserted strips may swell and buckle, or may shrink and slip out of the flanges.
Covers for vertical blind louvers also have been proposed. U.S. Pat. No. 4,911,220, to Hiller shows a vertical blind cover which is closed at the bottom, and secured at the top with extensions and snaps. However, adding narrow extension tabs and snaps to a simple tube increases manufacturing difficulty and price. In addition, Hiller makes no provision for a popular feature of vertical blinds: the attachment of chains and weights to the vertical blinds to keep them in place in wind. Such chains usually are attached to one side of a louver and connect each louver to neighboring louvers. The connections are one to two inches from the bottom edges of the vertical blinds. The chain usually is out of sight, being strung along the surface of the vertical blind system facing the window or door.
Some manufacturers offer blinds with two chains, which are attached to both lower side edges of the louvers. In that event, there is a chain running along the lower edge of the blinds on the window/door surface of the system and another chain on the surface visible from inside the room.
Cloth louvers also have been proposed. U.S. Pat. No. 4,309,472 to Gotting et al. teaches the manufacture of louvers from flame-retardant-treated polyester that has been permanently stiffened by plastification. Once treated, the special material is cut into slats. This material has the advantage over plastic or wood louvers of being transparent to light.
What is needed is a louver cover which is simple in design, eliminating expensive extensions and snaps, but adapted to accommodate the use of chains and/or weights.